2-aliphatic-1, 3-di (4-pyridyl)-2-propanols



United States PatentOffice 3,398,156 2-ALIPHATIC-1,3-Dl(4-PYRIDYL)-2-PROPANOLS Bernard Brust, Parsippany, Troy Hills, and Rodney Ian Fryer, North Caldwell, and Leo Henryk Sternbach, Upper Montclair, N.J'., assignors to Hofimann-La Roche Inc., Nutley, N.J., a corporation of New Jersey No Drawing. Continuation-impart of application Ser. No. 465,706, June 21, 1965. This application June 28, 1967, Ser. No. 649,453

6 Claims. (Cl. 260 296) ABSTRACT THE DISCLOSURE Pharmacologically active 1,3-di(4-pyridyl)-2-propanols having a 2-12 carbon aliphatic substituent on the 2-carbon are prepared by the reaction of a picolyl metal compound and an aliphatic acyl derivative.

Related applications This application is a continuation-in-part of application Serial Number 465,706 filed June 21, 1965, now abandoned, which is in turn a continuation-in-part of application Serial Number 344,249 filed Feb. 12, 1964, now abandoned.

Detailed description of the invention in which the symbol X represents the alkyl, alkenyl and 3,398,156 Patented Aug. 20, 1968 employed per dose level. The test compounds were administered orally and one-half hour later 20 ing/kg. of Tremorine was administered intraperitoneally. The Tremorine-treated mice were observed for 30 minutes. Animals not exhibiting tremors within this time were considered protected. The ED is calculated by the meth 0d of Miller and Tainter (Proc. Soc. Exptl. Biol. Med, volume 57, p. 261, 1944).

As a further illustration of this anti-tremorine activity of the compounds of this invention other exemplary compounds were active in the above-described test as follows.

Compound: ED (mg/kg.) 2-heptyl-1,3-di(4-pyridyl)-2-propanol 149 2-benzyl-1 ,3-di (4-pyridyl -2-propanol 11 By way of comparison the known anti-Parkinson agent a-cyclohexyl-u-phenyl-l-piperidine propanol exhibits activity in the above-described anti-tremorine test at an oral dose of about 19 mg./ kg.

The compounds of this invention have also demonstrated high potency and long duration of action in reducing hypothermia induced by Tremorine in mice. The effectiveness of the compounds of this invention against Tremorine-induced hypothermia in mice was determined by administering Tremorine intraperotoneally to mice at a level of 5 mg./kg. Rectal temperatures were taken before treatment and after treatment. Test compounds were administered orally and the Tremorine was administered 15, 45, 105, 165, 225 and 285 minutes later. The temperatures were then taken 15 minutes following administration of the Tremorine. Six mice were used for Tremorine control effects during the tests and 16 mice were used for each compound at each test interval. Activity was determined by calculation of the percent protection by drawing activity lines on graph paper using the method of least squares. The results for illustrative compounds of this invention are given below. For comparison the activity of the known anti-Parkinson agent a-cyclohexyl-a-phenyl-l-piperidine propanol when tested alkynyl residue of a straight or branched chain aliphatic by the same method is also given.

PERCENT PROTECTION AGAINST HYPOTHERMIC EFFECTS OF TREMORINE Dose Percent Protection e/ p.o. 0.5 hr. 1 hr. 2 hr. 3 hr. 4 hr. 5 hr.

a-Cyclohexyl-a-phenyl-l-piperidine propan 30 96. 1 91. 9 83. 4 74. 9 66. 5 58 2-isopropyl-l,3-di(4-pyridyl)-propanol 30 99. 8 96. 0 88. 4 80. 9 73. 3 65. 8

hydrocarbon having, for example, from 2 to 12 carbon atoms or an aralkyl radical, or a methyl radical.

Additionally, the invention encompasses salts of the Formula I compounds with medicinally acceptable acids, 'such as, hydrochloric acid, sulfuric acid, p-toluene sulfonic acid, etc.

The compounds of Formula I as well as the acid addition salts thereof relieve or diminish tremors which are brought about in animals by Tremorine, i.e., 1,4-dipyrrolidino-Z-butyne, with a minimum of peripheral anticholinergic side effects. Additionally, they reduce hypothermia produced by Tremorine. Thus, the compounds are indicated for use in the study of the treatment of tremors which are characteristicof P-arkinsons disease.

For example, the compounds of this invention when adiinnistered orally to animals such as mice relieve Tremorine-induced tremors in single dose amounts ranging between about 11 and about 150 mg./kg. By way of illustration, the compound 2-methyl-1,3-di(4-pyridyl)- 2-propanol which has an LD of greater than 420 mg./ kg. orally in mice exhibits activity in the anti-tremorine test .When administered at a single oral dose of 11 mg./kg. The anti-tremorine test employed in determining anti- Parkinson activity was carried out as follows: I

Six mice of both sexes weighing 17 to 22 grams were Thus, the compounds of this invention have demonstrated pharmacological effects in warm blooded animals qualitatively similar in many respects to those of a-cyclohexyl-m-phenyl-l-piperidine propanol, well-known for its therapeutic uses and properties.

Furthermore, the compounds of this invention alter the activity of the liver microsomal drug metabolizing enzymes. For example, they inhibit the following enzymatic oxidative reactions: hexobarbital to ketohexobarbital, acetanilid to p-hydroxyacetanilid, amphetamine to phenylacetone, clilantin to its p-hydroxy derivatives, etc. On prolonged administration the compounds of this inthe activity of the liver microsomal drug metabolizing drug metabolizing enzymes. Because of their activity, these compounds provide a valuable tool for the study of the drug metabolizing enzyme systems associated with the liver microsomes and are useful in the study and treatment of diseases caused by metabolic failures of such enzyme systems, for example, in the treatment of phenylketonuria.

The activity of the compounds of this invention in altering the liver microsomal drug metabolizing enzymes was first established by in vitro experiments on rat liver microsomal enzyme fractions the results of which are set forth in the examples hereinbelow.

The compounds of this invention are readily obtainable. A preferred procedure comprises reacting a picolyl metal compound having the formula (I) I-IzM in which R represents an alkyl group having from 1 to 12 carbon atoms, an alkenyl group having from 2 to 12 carbon atoms, an alkynyl group having from 2 to 12 carbon atoms, or an aralkyl group. In carrying out the invention, there is used preferably a ratio of at least about 2:0 moles of the picolyl metal compound of Formula II for each mole of the acyl halide employed. Obviously, however, a larger or smaller quantity of the picolyl metal compound can be used, if desired.

Thus, in preparing the compounds of this invention, one may employ as the 4-picolyl metal starting material of Formula II, 4-picolyl sodium, 4-picolyl potassium or 4-picolyl lithium. In the preferred embodiment of the invention, however, 4-picolyl lithium is used. As the acyl halide, there can be used, for example, acetyl chloride, isobutyryl chloride, octanoyl chloride, -undecenoyl chloride, phenylacetyl chloride, etc.

Alternate methods are available for preparing the present compounds. For example, the compounds can be obtained by reacting the Formula II compound with an ester having the formula RCOOR IV in which R has the same meaning as in Formula III and in which R represents an alkyl, phenyl or benzyl radical.

Thus, in such a method, the Formula II compound is reacted with an alkyl ester, such as, a methyl, ethyl, propyl, butyl, etc. ester of, for example, acetic acid, isobutyric acid, octanoicacid, IO-undecenoic acid, etc.; or with a benzyl or phenyl ester of such an acid.

In producing the present compounds, the 4-picolyl metal compound is, in a first step, dissolved in a suitable solvent. In general, the invention embraces the use of any organic solvent in which the 4-picolyl metal compound is soluble, and which is, at the same time, inert under the reaction condition employed. Solvents are suitable for use including, for example, benzene, diethyl ether, toluene, 4-picoline, tetrahydrofuran, etc. In the preferred embodiment of the invention, there is used a solution of 4-picolyl lithium in tetrahydrofuran.

The organic solvent solution of the 4-picolyl metal compound, the production of which is described in the preceding paragraph, is cooled byappropriate means to a temperature below room temperature. In the preferred embodiment of the invention, the solution of the 4-picolyl metal is cooled to a temperature within a range of from about 10 to -60 C. To the cooled solution, there is added the acid halide reactant of Formula III or the ester reactant of Formula IV, such reactant also being dissolved in a suitable solvent. In general, there is used any organic solvent in which the acid halide or ester in use is soluble and which is inert under the reaction conditions employed. Such solvents include, for example, ethyl ether, n-butyl ether, dioxane, tetrahydrofuran, etc., either alone or in a mixture with other organic solvents in which the acid halide or ester is soluble and which is inert under the reaction condition employed.

The addition of the acid halide or ester solution to the 4-picolyl metal solution is carried out slowly, for example, in a dropwise fashion under an extended period of time. The reaction mixture is stirred continuously until thedesired reaction has been'completed. The reaction mixture is subsequently worked up, by appropriate means, to isolate the compound produced. In one such isolation procedure, the reaction mixture is diluted with water and extracted with a suitable acid. As the extracting acid one can use, for example, an inorganic acid, such as, hydrochloric acid, sulfuric acid, phosphoriciacid, etc. The acid extracts are then. washed with an appropriate solvent, for example, an ether. The.desired product is obtained from the :w'ashedacid extracts by stirring same into a mixture of ice and suitable alkali. While any inorganic base can be used in this step of the process, for example,

. sodium hydroxide, potassium hydroxide, etc., ammonium hydroxide has been found tobe especially well suited for use. During the liberation of the reaction product, ice is used to keep the temperature of the mixture'at about 0 c. v

As indicated heretofore, the compounds of this invention are useful, inter alia', in the study and treatment of diseases caused by metabolic failures of enzyme systems. The manner in which they are used for such purpose will be readily apparent to persons skilled in the art. In general, the compounds can be formulated, with conventional inert adjuvants, into dosage forms suitable for oral or parenteral administration. Such dosage forms include tablets and capsules as well as solutions and suspensions. The frequency of administration is variable, depending upon the needs and requirements of the patient.

For a fuller understanding of the nature and objects of this invention, reference may be had to the following examples which are given merely as further illustrations of the invention and are not to be construed in a limiting sense.

Example 1 In this example, there was prepared a solution of 0.5 mole of 4-picolyl lithium in tetrahydrofuran. This solutron was brought to a temperature within the range of from about 30 to 50 C. To this cooled solution there was added, under an atmosphere of dry nitrogen, 0.2 mole of acetyl chloride dissolved in 150 ml. of tetrahydrofuran. This addition was effected in a dropwise fashion over a period of about sixty minutes. Thereafter, the reaction mixture was stirred overnight, following which it was diluted with ml. of water. The reaction mixture was then extracted three times using 150 ml. of 6 N hydrochloric acid each time. The acid extracts were then stirred into a mixture of 500 grams of ice and 300 ml. of concentrated ammonium hydroxide with the temperature being maintained at about 0 C.

The clear solution, obtained as described in the preceding paragraph, was thereafter extracted three times, using 150 ml. of methylene chloride each time. The orgame extracts were combined, dried over magnesium sulfate and reduced, in vacuo, to an oil. T rituration with hexane yielded 2- methyl-1,3-di(4-pyridyl)-2-propanol as yellow crystals melting at to C. Recrystallizatron of the product three times from an acetone-hexane mixture yielded the compound, in the form of colorless blocks, melting at 127 to 128 C.

Example 2 Example 3 In this example, Z-heptyl-l,3-di(4-pyridyl)-2-propano1 was prepared by the procedure set forth in Example 1, using octanoyl chloride as the acid halide reactant. The precipitate, which was formed when the acid extracts weretreated withice and concentrated ammonium hydroxide, was filtered and air dried. Thereafter, the dry product was washed with 500 ml. of hot hexane. Recrystallization of the product, three times, from acetonehexane yielded 2-heptyl-1,3-di(4-pyridyl)-2-propanol, in the form of colorless plates, melting at 102 to 104 C Example 4 Example 5 In this example, 2-(9-decenenyl)-1,3-di(4-pyridyl)-2- propanol was prepared by the method set forth in Example 1 using lO-undecenoyl chloride as the acid halide reactant. The precipitate, which formednwhen the acid extracts were treated with ice and ammonium hydroxide, was separated from the reaction mixture by filtration. The compound was crystallized from hexane to yield crude 2-(9-decenenyl)-1,3di(4-pyridyl)-2-propanol, melting at 63 to 66 C. Upon recrystallization from hexane, there was obtained 2-(9-decenenyl)-1,3-di(4-pyridyl)-2-propanol in the form of colorless needles melting at 66 to 69 C.

Example 6 This example is included herein to demonstrate the preparation of dosage forms containing as the active ingredient, a representative compound of this invention.

(a) Capsule formulation: 25 mg. of 2-isopropyl1,3- di(4-pyridyl)-2,-propanol were mixed with 150 mg. of lactose, U.S.P. and 30 mg. of corn starch, U.S.P. The mixture was then blended by passing through a Fitzpatrick Comminuting Machine with a No. 1A screen with knives forward. The blended powder was, thereafter, returned to the mixer and 5 mg. of talc was added thereto and blended therewith. The product was subsequently filled into hard shell gelatin capsules.

(b) Tablet formulation: 51 mg. of 2-isopropyl-1,3- di(4-pyridyl)-2-propanol were mixed with 243 mg. of lactose, U.S.P., 33 mg. of corn starch and 3 mg. of magnesi-um stearate. The mixture was blended by passing through a Fitzpatrick Comminuting Machine, fitted with a No. 1A screen with knives forward. The powder was then slugged on a tablet compressing machine, following which the slugs were comminuted using a No. 16 screen. The mixture was compressed at a tablet weight of 330 mg. using tablet punches having a diameter of approximately /s-in.

(c) Parenteral formulation: 2.5 mg. 2-isopropyl-l,3- di(4-py-ridyl)-2-propanol were slurried in a small amount of water. To the slurry there was added slowly tartaric acid to pH of 3.0. Thereafter, 4.5 mg. of phenol (anhydrous) was added to the solution. The solution was filtered and allowed to stand for twenty-four hours. Thereafter, the filtrate was filtered through a 02 Selas candle. The filtrate was then filled into ampuls, under an atmosphere of nitrogen, which were then sealed.

Example 7 This example is included herein to demonstrate the preparation of dosage forms, containing as the active ingredient, another representative compound of this invention.

(a) Capsule formulation: 25 mg. of 2-heptyl-1,3-di(4- pyridyl)-2-propanol were mixed with mg. of lactose, U.S.P. and 30 mg. of corn starch, U.S.P. The mixture was then blended by passing through a Fitzpatrick Comminuting Machine with a No. 1A screen with knives [forward. The blended powder was, thereafter, returned to the mixer and 5 mg. of talc was added thereto and blended therewith. The product was subsequently filled into hard shell gelatin capsules.

(b) Tablet formulation: 51 mg. of 2-heptyl-1,3,-di(4- pyridyl)-2-propanol were mixed with 243 mg. of lactose, U.S.P., 33 mg. of corn starch and 3 mg. of magnesium stearate. The mixture was blended by passing through a Fitzpatrick Comminuting Machine, fitted with a No. 1A screen with knives forward. The powder was then slugged on a tablet compressing machine, following which the slugs were comminuted using a No. 16 screen. The mixture was compressed at a tablet weight of 330 mg. using tablet punches having a diameter of approximately Vs inch.

(c) Parenteral formulation: 2.5 mg. of 2-hepty1-1,3- di(4-pyridyl)-2-propanol were slurried in a small amount of water. To the slurry there was added slowly tartaric acid to pH of 3.0. Thereafter, 4.5 mg. of phenol (anhydrous) were added to the solution. The solution was filtered and allowed to stand for twenty-four hours. Thereafter, the filtrate was filtered through a 02 Selas candle. The filtrate was then filled into ampuls under an atmosphere of nitrogen, which were then sealed.

Example 8 Experiment A.10 CF-l male mice weighing approximately 20 grams were treated with 2-methy1-1,3 di(4- pyridyl)-2-propanol, 50 mg./kg., i.p. One hour thereafter, 150 mg./ kg. of sodium hexobarbital was administered intraperitoneally to each test animal.

Experiment B.10- CF-l male mice weighing approximately 20 grams were treated with 2-isopropyl-1,3-di(4- pyridyl)-2-propanol, 50 mg./kg., i.p. One hour thereafter, 150 mg./ kg. of sodium hexobarbital was administered to each test animal.

Control experiments.For each of Experiments A and B control experiments were conducted wherein 10 CF male mice, previously untreated and weighing approximately 20 grams, were injected intraperitoneally with 150 mg./kg. of sodium hexobarbital.

In carrying out the experiments the test animals were observed until they reached a sleeping state. After reaching 'a sleeping state the animals were placed on their backs and their sleep was observed. The criterion for wakefulness was the ability of the animal to right itself. Once the animal had righted itself it was again turned on its back in order to check whether this phenomena was spasm or the actual return of the righting reflex. The time at which these two rightings were performed consecutively was considered the end of the experimental sleeping time.

The average of the sleep-ing time of the test animals in each experiment and the average of the sleeping time of the animals in each control experiment is set forth below:

Experiment A '360 minutes.

Experiment A Control42:7 minutesistandard deviation.

Experiment B 300 minutes.

Experiment B Control39-+ -8 minutesistandard deviation.

The activity of the compounds of this invention in altering the liver microsomal drug metabolizing enzymes was also shown by in vitro experiments as follows:

Preparation of liver enzyme fractions (microsomes plus soluble supernatant fluid).Male albino rats of the Charles River strain weighing between 150 and 250 grams were sacrificed by cervical dislocation and the livers were quickly removed and placed on cracked ice. The livers were weighed and a 1:2 (W./v.) homogenate in 0.1 molar sodium d-ihydrogen phosphate-potassium monohydrogen phosphate, pH 7.4, was prepared in an ice-cooled Waring Blendor. The liver was homogenized for a Period of about thirty seconds and the resulting homogenate was centrifuged at 1,000 times gravity for a period of thirty minutes at a temperature of C. in an International refrigerated centrifuge, Model ER-2. The supernatant was further centrifuged at 9,000 times gravity for a period of twenty minutes at a temperature of 0 'C. in a Spinco Model L ultracentrifuge. The supernatant fraction which contained the microsomes and the soluble cellular material was used in the study hereinafter described.

In the study a reaction mixture was prepared using 2 ml. of the enzyme fraction obtained as described in the preceding paragraph, a substrate of 0.5 ml. of sodium hexobarbital, 1.0 ml. of a solution containing 2 nmoles of triphosphopyridine nucleotide and 20 ,umoles of glucose-6-phosphate disodium salt, 40 moles of n-icotinamide hydrochloride and 20 ,amole's magnesium chloride, 0.5 ml. of a standard solution of inhibitor, i.e., a compound of Formula I above, and the mixture was adjusted to a final volume of 5.0 ml. with 0.1 molar sodium dihydrogen phosphate buffer, pH 7.4. In the preparation of this reaction mixture, the ingredients, except the substrate, i.e., sodium hexobarbital, and the inhibitor were p-reincu-bated for a period of about fifteen minutes at a temperature of about 37 C. under a mixture of 95 percent oxygen-5 percent carbon dioxide. After the addition of the substrate and inhibitor, the mixture was incubated for a period of about fifteen minutes under the same conditions. The reaction was terminated by placing 3 ml. of the incubation tube containing 20 ml. of hexane (washed with 0.5 volume of 0.1 molar sodium dihydrogen phosphate butter, pH 5.5), 1.5 grams of sodium chloride and 1.0 ml. of 0.1 molar sodium dihydrogen phosphate buffer (washed with 2 volumes of heptane), pH 5.5.

In each experiment, a zero time tube and a blank tube were run. The zero time tube was prepared as follows: one ml. of a solution containing 2 ,umoles of triphosphopyridine nucleotide, 20 ,umoles of glncose-6-lphosphate disodium salt and 20 ,umoles of magnesium chloride were incubated for a period of fifteen minutes With 2 ml. of enzyme and 1.5 ml. of 0.1 molar sodium dihydrogen phosphate buffer, pH 7.4. An aliquot of 2.7 ml. of the incubation mixture and 0.3 ml. of substrate was added to a centrifuge tube containing the heptane extraction mixture described heretofore. The blank tube was prepared in the same way as the zero time tube except that 2.0 ml. of buffer was used. The blank tube was preincubated for a period of about fifteen minutes and incubated for a period of about fifteen minutes.

The hexobarbital was extracted by vigorously shaking the reaction mixture containing the heptane, sodium chloride and buffer for a period of about forty-five minutes in an International Bottle shaker, following which it was centrifuged at 1,000 times gravity for a period of about twenty minutes at a temperature of about 20 C. The supernatant (heptane) was removed with a 10 ml. pipette, with a suction bulb attached, and it was placed in another 50 ml. ground glass stoppered centrifuge tube containing 5.0 ml. of 0.1 molar sodium dihydrogen phosphate buffer (washed with 2 volumes of heptane) of pH 5.5 The tubes 8 were shaken by hand for a period of about fifteen seconds and then allowed to stand until the phases separated. Fifteen ml. of the resulting supernatant was placed in a 50 ml. ground glass stoppered centrifuge tube and-4 ml. of 0.8 molar sodium monohydrogen phosphate, pH 11 (adjusted with 5.0 molar sodium hydroxide), was added and the tubes were shaken for a period of about three minutes on the International Bottle shaker. After centrifuging the tubes for a period of about three minutes at 1,000 times gravity, the buffer phase was'removed with a 5 ml. pipette and transferred to a silica cuvette. The absorbency of the solution at 245 m was read in a Beckman D.U. spectrophotometer against a blank containing the pH buffer. A standard solution of sodium hexobarbital (20 ,ug/ml.) was used. The absorbance of this solution was about 0.590.

From the absorbancy data thus obtained there was calculated the extent to which the compounds of Formula I inhibited the oxidation of hexobarbital by the rat-liver microsomal enzyme fraction. The results for representative compounds of Formula I are shown below.

Concentration Percent Compound nmoles/liter Inhibition Z-methyl-l,3-di(4-pyridyl)-2-propanol 10 22 2-benzyl-1,3-di(4-pyridyl)-2-propanol 10 66 in which X is a member selected from the group consisting of alkyl having from 1 to 12 carbon atoms,

alkenyl having from .2 to 12 carbon atoms, alkynyl having from 2 to 12 carbon atoms and benzyl and salts thereof with medicinally acceptable acids.

2. A comlpound according to claim 1 wherein X is methyl i.e. the compound 2methyl-1,3-di(4-pyridyl)-2- propanol.

3. A compound according to claim 1 wherein X is isopropyl i.e. the compound 2-isopropyl-l,3-di(4-pyridyl)-2- propanol.

4. A compound according to claim 1 wherein X is heptyl i.e. the compound 2-heptyl-l,3-di(4-pyridyl)-2-propanol.

5. A compound according to claim 1 wherein X is benzyl i.e. the compound 2-benzyl-1,3-di(4-pyridyl)-2-propanol.

6. A compound according to claim -1 wherein X is 9- decenenyl i.e. the compound 2-(9-'decenenyl)-l,3-di(4 pyridyD-Z-propanol.

References Cited Chemical Abstracts, Vol. 64, par. 15, 855-15, 856, May 1966 (abstracting Netherlands published specification S.N. 6508725).

HENRY R. JILES, Primary Examiner.

A. I. ROTMAN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,398 ,l56 August 20 1968 Bernard Brust et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, lines 34 to 38, formula I should appear as shown below:

same column 1, line 63, "adimnistered" should read administered Column 2, line 9, "this" should read the line 25, "intraperotoneally" should read intraperitoneally lines 59 and 60, after "this" insert invention stimulate line 61, cancel "drug metabolizing", second occurrence.

Signed and sealed this3rd day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

